title: Cognitive factors modulate activity within the human subthalamic nucleus during voluntary movement in Parkinson's disease.
abstract: Movement is accompanied by changes in the degree to which neurons in corticobasal ganglia loops synchronize their activity within discrete frequency ranges. Although two principal frequency bands--beta (15-30 Hz) and gamma (60-90 Hz)--have been implicated in motor control, the precise functional correlates of their activities remain unclear. Local field potential (LFP) recordings in humans with Parkinson's disease undergoing surgery for deep brain stimulation to the subthalamic nucleus (STN) indicate that spectral changes both anticipate movement and occur perimovement. The extent to which such changes are modulated by cognitive factors involved in making a correct response seems critical in characterizing the functional associations of these oscillations. Accordingly, by recording LFP activity from the STN in parkinsonian patients, we demonstrate that perimovement beta and gamma reactivity is modulated by task complexity in a dopamine-dependent manner, despite the dynamics of the movement remaining unchanged. In contrast, spectral changes occurring in anticipation of future movement were limited to the beta band and, although modulated by dopaminergic therapy, were not modulated by task complexity. Our findings suggest two dopamine-dependent processes indexed by spectral changes in the STN: (1) an anticipatory activity reflected in the beta band that signals the likelihood of future action but does not proactively change with the cognitive demands of the potential response, and (2) perimovement activity that involves reciprocal beta and gamma band changes and is not exclusively related to explicit motor processing. Rather perimovement activity can also vary with, and may reflect, the cognitive complexity of the task.
authors.affiliation: Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford OX9 3DU, United Kingdom, Wellcome Trust Centre for Neuroimaging, London WC1N 3BG, United Kingdom, and Department of Neurology, Department of Neurosurgery, Charité-University Medicine Berlin, 10177 Berlin, Germany.
authors.forename: Ashwini
authors.initials: A
authors.lastname: Oswal
authors.forename: Vladimir
authors.initials: V
authors.lastname: Litvak
authors.forename: Christof
authors.initials: C
authors.lastname: Brücke
authors.forename: Julius
authors.initials: J
authors.lastname: Huebl
authors.forename: Gerd-Helge
authors.initials: GH
authors.lastname: Schneider
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Kühn
authors.forename: Peter
authors.initials: P
authors.lastname: Brown
mesh_terms: D000328:Adult; D000978:Antiparkinson Agents / Q000494:pharmacology / Q000627:therapeutic use; D001611:Beta Rhythm / Q000187:drug effects / Q000502:physiology*; D001931:Brain Mapping; D003071:Cognition / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010300:Parkinson Disease / Q000188:drug therapy / Q000503:physiopathology*; D020531:Subthalamic Nucleus / Q000187:drug effects / Q000503:physiopathology*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa